ES2170713B2 - METHOD OF MANUFACTURE OF A COLLAGEN MEMBRANE FROM SWINE SKIN. - Google Patents

Abstract

Method of manufacturing a collagen membrane from pig skin. Collagen membranes are formed from pig barks (ie pig skins) for use in a wide variety of applications and; more preferably, to sheath food products, such as hams and the like. According to the method of the invention, first, after removing the skins from the pig, the skins are quickly frozen. In a subsequent treatment, the crusts are thawed and then enzymatically degreased. Next, the crusts are subjected to rapid alkaline hydrolyzing. Next, the barks are subjected to acidic hydrolyzing. The crusts are then milled in the form of a geliform fluid mass. Finally, the fluid mass is extruded, laminated and dried until a collagen membrane is obtained. The collagen membrane obtained can be used, in preferred embodiments, to sheathe foodstuffs, such as hams.

Description

Method of manufacturing a collagen membrane from pig skin.

Background of the invention Technical sector of the invention

The present invention refers generically to the manufacture of collagen membranes and, more specifically, to the manufacture of edible collagen membranes to sheath food products, such as hams and the like.

Description of the known technique related to invention

Collagen membranes (also called: films, sheets, etc.) are used in a variety of Applications, as illustrated in US Pat. Nos: US 5,736,180 (Edible sheath impregnated with spices); US 5,520,925 (Material based on collagen fibers for wound coating); US 5,190,810 (Composite for use in the manufacture of protective articles for use in laser surgery); US 5,103,816 (Composite for use in the manufacture of articles protectors for use in laser surgery); US 5,028,695 (Process for the manufacture of collagen membranes used for hemostasis, dressings for wounds and for implants); US 4,131,650 (Sheet of collagen for cosmetic applications).

As illustrated in the cited US patent 5,736,180, some edible collagen sheets are known for, among other uses, the sheathing of food products, such as hams

Collagen sheets can be made of A variety of animal skins. However, the manufacture of Collagen sheets from pig skins (i.e. pig skins) presents a certain amount of problems individuals with respect to the manufacture thereof, by example, from beef or cattle. For example, they may arise problems derived from the need to eliminate pig hair and to treat the high fat content of the skins of porcine.

Currently, there are some procedures for the preparation of collagen sheets from pig skins, but these procedures are not satisfactory for preparation of food products and the like from the sheet of collagen produced. Existing procedures are on track to the preparation of pig skins for the creation of `` Tannery '' items that are processed in would have or Similar.

At present, collagen sheets are prepared from pig skins as indicated in the following paragraphs (a) to (c). The present invention is a great Progress with respect to existing procedures. Specific, Existing procedures use the following steps:

(to)

The skins of pigs are collected from a slaughterhouse (i.e. from the establishment where animals are sacrificed) and are normally preserved with sodium chloride and are sold by skin wholesalers at would you have (i.e. fur processing industries in tanned). In the shops, the items are first washed with water and wetting agents and, if necessary, are used also enzymes to eliminate adherent feces and sodium chloride. In other additional steps the hair is removed from the skin using sodium sulfide and quicklime and, if necessary, using enzymes and lubricants As a result, the skins (which are alkaline) are swell to a thickness of between about 5 and 10 mm

(b)

To continue on treatment of the skins and transform them into leather, the skins are They `` divide '' horizontally into two layers. The bottom layer, that is the one that faces the animal's body, serves as Raw material for the manufacture of collagen sheets. Depending on the would have, as an intermediate step, the material can stored often for an indefinite period under conditions lacking hygienic control.

(C)

Layers or halves are then subjected to a caustic soda solution and / or quicklime in an alkaline hydrolyzing process that can last up to 15 days By the hydrolyzing process, the material remains prepared for additional steps, particularly of trituration. Due to the molecular characteristics of collagen of bovine skin that is used (reticular structure), are required hydrolyzing processes that go from intense to aggressive. Behind the alkaline hydrolyzing, layers or halves are brought to pH <3.5 after having previously undergone an acidic treatment strong, for example with hydrochloric acid, and then they are milled until giving them a geliform consistency. Alternatively, after alkaline treatment, the skins are taken at a pH between 5 and 7 using organic or inorganic acids, milled in the form of pulp fibrous and brought to pH <3.5. The fluid pulp, which contains less of 2.5% collagen and to which other materials have been added, such as glycerin, Karion® (sorbitol) and agents cross-linking, is extruded and dried in a belt dryer to Get the sheet.

The procedures just described They have significant disadvantages. In a general way, those present inventors have found that the above procedures are not satisfactory for food products and the like. The present inventors have found that the above procedures they have, for example, the following specific disadvantages:

-

Salts preservatives may have additives that should not appear in foods.

-

The skins don't know Wash and store with faecal contamination.

-

Gender can be of doubtful origin (that is, in the fur trade, there are also gender of doubtful origin, such as for example of killifes).

-

The treatment in the would have is based on leather production requirements using technical chemicals.

-

The product is transported in conditions lacking refrigeration to sheet manufacturers. As a consequence, in most seasons warm, there is a potential increase in bacterial contamination. This contamination may even be sufficient to cause partial rot of the transported material. Alkaline product may also be subject to chemical decomposition uncontrolled, depending on temperature conditions and interval of time elapsed between cutting and delivery to sheet manufacturers.

-

Raw material for the sheets it is subject to extreme quality variations due to the complex succession of events that take place.

-

The treatment aggressive alkaline (hydrolyzing) also leads to alterations of denaturation of collagen.

Summary of the Invention

In view of the previous problems of the existing technique, the present invention was devised by present inventors to give solution to those mentioned and others problems that occur in the manufacture of membranes collagen, and especially in the manufacture of collagen membranes edible from pig skins (also called: skins or pork rind).

The present invention provides, among others things: a) a new method for manufacturing a membrane of collagen; b) a new collagen membrane manufactured by the method; and c) a new method of using the membrane of collagen

According to a first aspect of the invention, provides a method of manufacturing a collagen membrane to from pig bark, which includes the steps of: removing the pig skins and freeze them for treatment- defat enzymatically the barks; subject the barks to a rapid alkaline hydrolyzing; subject the barks to a acidic hydrolyzing; grind the crusts in the form of a dough geliform fluid; and extrude, spread and dry the geliform mass in the shape of a collagen membrane.

According to another aspect of the invention, a membrane of collagen is manufactured by the method of the first aspect of the invention. In a preferred embodiment, the collagen membrane is available as a cover around a food product, such Like a ham

The above and other aspects, characteristics and advantages of the invention will be better understood based on the following description of the preferred embodiments, in combination with the accompanying drawings and claims.

Brief description of the drawings

The present invention is illustrated by way of non-limiting example in the attached drawings, in which the Same references indicate the same parts, and in which:

Fig. 1 is a schematic drawing showing the finished sheet on a product, such as a ham or other meat product

Detailed description of the preferred embodiments

As stated before, the present invention provides, among other things: a) a new method for manufacture of a collagen membrane; b) a new membrane of collagen manufactured by the method; and c) a new method of use of the collagen membrane.

Product manufacturing method

The first aspect of the present invention assumes a new method of manufacturing a collagen membrane (which It can also be called foil, film, etc. of collagen). Briefly, according to a first embodiment, the method preferably includes the following general method steps (the sequence of steps may vary):

(to)

collection / freezing of bark

(b)

chemical degreasing of the barks

(C)

treatment alkaline / elimination (also called removal) of hairs

(d)

treatment acidic

(and)

formation of a geliform mass

(F)

extrusion / drying

(a) Immediately after removing the barks of pigs in the slaughterhouse (that is, quickly after of removing or starting them, for example, by means of clearing, of the bark of the pigs in the slaughterhouse facilities), the barks are washed with hot or cold water and removed from them the hairs. After that, the crusts are quickly frozen to be used as raw material in the process of obtaining collagen membranes Preferably, the crusts are frozen quickly in very clean conditions, thus being preserved for later use. A variety of techniques can be applied freezing, such as for example, subjecting the crusts to a fast freezer at -50ºC or a normal freezer at between -18 and -28 ° C. It is also possible to subject the crusts to dry ice or liquid nitrogen. It is equally possible to start the process directly with new crusts without freezing.

Preferably, the crusts are kept in this state of freezing until they are subsequently treated as explained below. In this regard, the subsequent treatment steps are typically carried out in a location other than the slaughterhouse and, therefore, the crusts are transported, also preferably, in this state frozen. For subsequent treatment in stages, step (b) and following, explained below, preferably the barks frozen should be thawed to facilitate such treatment;

(b) In subsequent treatment, the crusts They are defatted in one or more steps. This degreasing is done preferably enzymatically with the help of wetting agents (for example, detergents). Before starting the chemical process, it is equally possible to degrease the crusts mechanically (suppression of fats greater than 15% of the initial fat content). Too degreasing with water and surfactant or with solvents is possible organic

(c) Then the treatment is carried out alkaline with organic or inorganic alkaline reactive agents, This treatment could be combined with the removal of the bristles swine Strong alkaline agents such as hydroxide sodium or potassium hydroxide are capable of dissolving the bristles and soften the fibrous structure of collagen. The agents inorganic or organic reducers such as sulfides (for example, sodium sulfide, potassium sulfide) or thio- compounds (for example, thioalcohols, thiourea, thioglycol) are also capable of dissolving the bristles.

(d) With acidic agents, the barks are carried at a maximum pH of 4.0 with inorganic acids (for example, acid hydrochloric, sulfuric acid, phosphoric acid) or organic (for example, lactic acid, citric acid, formic acid, acid acetic). During this treatment, the crusts absorb water (se swell). This is important for the transformation of the crusts in a geliform mass. It can also be neutralized with agents acidic reagents at a pH between 4 and 8, most preferably between 5 and 7. The resulting deflated material could be crushed in the form of a fibrous paste. Later, this paste is acidified up to pH <4 to adopt the geliform mass.

(e) Swollen barks are milled in the shape of a geliform mass. It is also possible to grind the non-swollen barks at pH> 4.0 in the form of a paste collagen and perform acidification until the geliform mass is obtained in a subsequent treatment.

(f) Then the fluid mass is treated in known extrusion and drying steps, which are analogous to those of prior art procedures used with skins of bovine, as here and previously explained.

The method of the present invention has advantages substantial with respect to existing procedures. Some of the advantages include by way of example that:

1. Advantageously, step (a) of the present method can

- provide a product that is appropriate for food products;

- provide a raw material for films that have a high and constant quality;

- avoid raw materials from sources not suitable for feeding;

- avoid loading or contamination of matter premium with chemicals;

- avoid loading or contamination of matter premium with microbiological contaminants;

- avoid uncontrolled chemical decomposition of the raw material; Y

- avoid microbiological decomposition Uncontrolled raw material.

(2) In steps (b) to (e), both the high fat content as the alkaline treatment comparatively not aggressive can also prevent alterations of denaturation in collagen. Moderate temperatures and Non-aggressive sizing steps also protect the collagen. With such resulting collagen material, it is possible to reduce or eliminate crosslinking agents in final product. On the contrary, the degraded collagen requires the use of crosslinking agents to obtain the desired tensile strength.

The method according to the first aspect of the invention may include, in the following illustrative examples and not limiting, the characteristics that are explained in greater detail described here and shown schematically in the figures. The illustrative cases are based on examples of embodiment that it has been produced.

In these embodiments, the treatment of pig hides after the step indicated above as (a) can include the specific procedural steps described to continuation. In the description that follows, the percentages are given with respect to the weight of the crusts (i.e. the weight of the crusts = 100%) and the `` mixer '' that was used was a stainless steel reaction vessel.

Example 1

He passed I

(Degreasing)

In a first step (after collection and freezing), very fatty crusts are degreased. This step of degreasing is preferably carried out with the help of wetting agents (eg detergents). For hydrolyze the natural fats present between the fibers of collagen, preferably lipases are used. Also, to help in this action (ie to provide more uniform degreasing) preferably proteases are used. In addition, to emulsify Released fatty acids a surfactant is preferably used. The combination of chemicals and biochemical agents used in this step, and the advantages that derive from it, were not previously contemplated in the field of sheet preparation or Edible movies

In a specific non-limiting example, this degreasing can be done as follows (should be understood that this is an exemplary embodiment and that it can be modified from the appropriate form by those skilled in the art, depending on the circumstances (the most preferable values are among parenthesis)):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ pH 7-11 (9-10) \\ (i) placing the following in the
Mixer \\ \ quad Barks \ + 100% \\ \ quad Water \ +
50 - 150% \ + (100%) \\ \ Sodium Carbonate \ +
0 - 5% \ + (3%) \\ \ quad Over fat solvents
(lipases): \ + 0 - 2% \ + (0.6%) \\ \ quad
Protein solvents (proteases): \ + 0 - 2% \ +
(0.5%) \\ (ii) Mixer treatment: \ + 30
min - 3h \ + (1 hour) \\ (iii) Add to the above in
the mixer \\ \ Quad Surfactant \ + 0,05 - 3% \ +
(0.5%) \\ (iv) Treatment time in the mixer: \ + 30
min - 5h \ + (2 hours) \\ (v) Rinse: \\ \ qquad Extract
of the mixer water and dissolved chemical products
(for example, through \\ \ qquad of a
drain). \ end {tabular}
      

He passed II

Alkaline treatment / hair removal (en say, suppression or removal of pig sows)

In a second step it is removed from the bristles pigs the hair (for example, the roots inside the skin). The presence of this hair is a particular problem in the case of Pigskins In this step of `` hair removal '', to dissolve these undesirable hairs or pig material is used a combination of chemicals, which preferably include sodium sulfide This step and the advantages that derive from it they are also unknown in the field of edible sheets, Normally, this hair removal step takes place in the You would have technical conditions. The use of sulfur in the elimination of pig sows under food conditions is new.

In a specific non-limiting example, this hair removal can be done as follows (the most preferable values are in brackets):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ pH> 9 (> 12) \\ (i) Place in the mixer \\ \ quad
Quicklime \ + 0.5 - 5% \ + (3%) \\ \ water \
20 - 50% \ + (30%) \\ \ Sodium sulphide \ +
2 - 6% \ + (4%) \\ (ii) Treatment time in the
mixer: \ + 2 - 8h \ + (5.5 h) \\ (iii) Add to
previous in the mixer \\ \ quad Water \ hfill rest up to \ + 100% \ +
(70%) \\ (iv) Treatment time in the mixer: \ +
5 - 30 min \ + (10 min) \\ (v) Rinse: \\ \ quad Remove
of the mixer water and chemicals
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

Alternatively, sodium sulfide, others inorganic or organic reducing agents such as sulfur potassium or thio- components, for example, thioalcohols, thiourea, Thioglycol, are also able to dissolve the bristles. The agent reducer / quicklime can also be replaced by an alkali strong, for example sodium hydroxide or potassium hydroxide only, to The removal of the bristles.

He passed III

(Washed)

Next, pig skins are preferably subjected to a washing step. In an example no limiting, the washing step can be carried out in the manner following (the most preferable values are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ (i) Place in the mixer: \\\ Water \ +
50 - 200% \ + (100%) \\ (ii) Treatment time in the
mixer: \ + 5 - 30 min \ + (10 min) \\ (iii)
Rinse: \\\ quad Remove water and products from the mixer
dissolved chemicals. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed IV

(Cleaning and preparation)

In a subsequent referred step, the bristles, preferably with peroxide, to tighten the bristles. Preferably sodium hydroxide is used in order to provide a alkaline state more favorable for peroxide action.

Sodium hydroxide also `` prepares '' the collagen structure - that is, it provides the first step of the separation of collagen fibers. While sodium hydroxide is already used in the treatment of collagen in the prior art, the `` preparation '' of bovine sows requires more concentrations high levels of sodium hydroxide and, especially, longer periods than for pig sows. The bovine sows collagen is more crosslinked, and the material is harder and requires a more energetic hydrolyzing for `` preparation '' than for pig bristles For example, in the present invention the bristles pigs can be treated with between 0.3 and 0.8% sodium hydroxide for 1 to 2 hours. Bovine sows need between 1 and 1.5% sodium hydroxide for between 12 and 24 hours or a quicklime suspension for at least 15 days.

In a non-limiting example, this step may be carried out as follows (the most preferable values are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30 ° C) \\ pH 8 - 13 (9 - 11) \\ (i)
Place in the mixer: \\ \ quad Water \ + 50 - 200% \ +
(100%) \\ \ Hydrogen peroxide (33 - 35%) \ +
0 - 2% \ + (1%) \\ \ Sodium Hydroxide \ +
0.3 - 0.8% \ + (0.6%) \\ (ii) Treatment time in
the mixer: \ + 1 - 2 h \ + (1 h) \\ (iii) Rinse: \\
Remove water and chemicals from the mixer
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed V

(Second wash)

Then the pig barks are preferably subject to a second washing step. In an example non-limiting, the second washing step can be carried out of the following way (the most preferable values are between parenthesis):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ (i) Place in the mixer: \\\ Water \ +
50 - 200% \ + (100%) \\ (ii) Treatment time in the
mixer: \ + 5 - 40 min \ + (20 min) \\ (iii)
Rinse: \\\ quad Remove water and products from the mixer
dissolved chemicals. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed SAW

(Acidification)

After alkaline treatment before described and preferably at this point, a brief is made acidic treatment In this step, a preparation is carried out additional - specifically, hydrolyzing of the unstable acid crosslinks, dissolving the material not acid soluble collagen of the bristles.

In a non-limiting example, acidification can be carried out as follows (more values preferable are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30 ° C) \\ pH max. 3.5 \\ (i) Place in the mixer: \\ \ quad Water \ +
30 - 150% \ + (70%) Hydrochloric acid (31 -
33%) \ + 2.5 - 10% \ + (7%) \\ (ii) Treatment time
in the mixer: \ + 15 min - 5 h \ + (2 h) \\ (iii)
Rinse: \\\ quad Remove water and products from the mixer
dissolved chemicals. \ hskipminus2cm \ end {tabular}
      

Other possible acids: sulfuric acid, acid phosphoric or organic acids, for example, lactic acid, acid citric, formic acid, acetic acid. Duration of this step: between 15 minutes and 5 hours.

He passed VII

(Additional wash)

The pig barks are then subjected preferably at an additional washing step. In an example no limiting, this additional washing step can be carried out by as follows (the most preferable values are between parenthesis):

         \ begin {tabular} {lcc} Temperature: 30ºC \\ (i)
Place in the mixer: \\ \ quad Water \ + 50 - 200% \ +
(100%) \\ (ii) Treatment time in the mixer: \ +
5 - 40 min \ + (20 min) \\ (iii) Rinse: \\ \ quad
Remove water and chemicals from the mixer
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

(iv) Repeat steps (i) to (iii) until obtaining a pH of approximately between 1.8 and 3.9. In this way, at increase the pH, the collagen absorbs water Thus, the material `` filler of water '' can be ground directly in the manner explained next, to obtain a geliform mass.

After this step, the washed bristles have preferably a pH of about 2.5 and a content in collagen of approximately between 13 and 21%.

Another possible way is a neutralization, instead of acidification. The material is milled in the form of a collagen paste that is then acidified to obtain a geliform mass (see Example 2).

He passed VIII

(Grinding)

The washed barks are preferably milled to obtain a uniform geliform mass. Although the milling of skins in a geliform mass is already known in the Collagen treatment, to improve grinding, preferably the size is reduced in at least three stages. From In this way, collagen fiber can be protected much better than compared to the same size reduction using only, For example, two stages. It should be noted that only small masses of collagen particles are not separated by adding Water.

In a non-limiting example, the step of Grinding can be carried out as follows:

one.

Dividing the barks in pieces of approximately one centimeter by crushing with plates with 10 mm holes or by cutting with blades

2.

Then dividing the pieces into small pieces of approximately ones few millimeters in diameter by crushing or pressing the material through a plate with 4 mm holes.

3.

Then, grinding up to <1 mm pressing through plates with holes <1 mm in diameter, or with the help of a colloid mill or a homogenizer

During these procedures water can be added or additional ice.

He passed IX

(Preparation of the fluid mass)

In a next step, the dough is preferably mixed with water and softener. A part of the water can be ice.

The softener includes, for example, dialcohols, trialcohols, polyols, (for example, glycerol) or sugars polymeric (for example Sorbitol and Karion).

The collagen preparation procedure It is very protective for collagen. Therefore, and which is An important fact, the collagen membrane of the invention does not normally requires crosslinking agents for stabilization and improvement of its mechanical properties.

However, if desired, the following Chemicals can act as crosslinkers: organic crosslinkers, for example di-aldehydes, α-hydroxyaldehydes, diisocyanates, bisacrylamides, acrolein, carbodiimides, anhydrides, diene, polyene; and inorganic crosslinkers, for example compounds of aluminum. To apply to the dough, the compounds are better slow and water soluble reagents (for example, di-aldehydes, α-hydroxyaldehydes). Reactive compounds water insoluble rapids should only be applied to the sheet dry

In a case of non-limiting example, the values of the fluid mass can be approximately (the most preferable are in parentheses):

         \ nobreak \ vskip.5 \ baselineskip \ centering \ begin {tabular} {lcc}
Collagen content: \ + 1 - 25% \ + (1.8%) \\
Glycerol: \ + 0 - 1% \ + (0.5%) \\ Sorbitol: \ +
0 - 1% \ + (0.2%) \\ pH: \ + 2 - 3.6
\ + (2.5%) \\ Temperature: \ + 3 - 18ºC \ + (8ºC)
\\\ end {tabular} \ par \ vskip.5 \ baselineskip
      

In relation to softening, it is of Note that pure and dry collagen films are fragile. He softening step creates a separation of the fibers of collagen that allows, for example, that fibers vary easily their positions with respect to adjacent fibers. In this sense, water is practically the best softener for the collagen The softeners mentioned above act indirectly - that is, they are very hygroscopic and keep water in the collagen However, these carbohydrates also have a significant inconvenience - which is that they accept growth microbiological, since they are a good available source of carbon.

Although fats are good softeners Directly, coating the dried collagen sheet with non-fat It is very effective. If this is done, fats are incorporated only between the fibers, and not within the fibers. The adition of fat emulsions inside the collagen mass It provides better results, but it has two drawbacks:

one.

on the sheet of collagen emulsifying agents are present; Y

2.

fat can migrate to the surface of the collagen sheet, since there is no left correctly set.

In preferred embodiments, the best Softener is the natural fat not removed. Preferably in In the present method, the chemical process is adapted in such a way that Do not remove all of the fat. The fat that remains is therefore used as a softener, so it only takes a small amount - or even none - of softener of carbohydrates In comparison with other processes, this invention works advantageously with pig pigs very fat

Fat suppression in the step or steps of degreasing depends on:

temperature

pH

weather

amount of lipase

amount of surfactant

number of steps of degreasing

position in the process

The degreasing is done more satisfactorily at a higher temperature (approximately 30 ° C), at a pH between 9 and 10, for extended periods of time (up to, for example, 6 hours), with higher amounts of lipase (up to 1%), higher amounts of surfactant (up to 3%), greater number of degreasing steps (up to 5 or more throughout the procedure) and more at end of processes, for example after alkaline treatment. The fat content not eliminated can be between 0 and 10% (of the dry weight of the sheet).

In relation to crosslinking agents, It should be noted that only unchanged natural collagen It manifests the best mechanical properties. In the proceedings high amounts of agents are necessary from the prior art crosslinking after normally strong alkaline processes of chemical treatment (that is, the hydrolysis of the molecules of collagen) Crosslinking agents are used to synthetically reconstruct larger molecules. With the present method, collagen molecules can be protected and limit crosslinking agents to a minimum amount.

He passed XII

(Homogenization)

Once the above is finished, preferably Perform a homogenization step. First the bubbles are removed of air, then the paste is passed to a homogenizer and then the material is pumped into steel containers stainless.

The importance from the chemical point of view of the homogenization is that it facilitates the uniform distribution of Water. Homogenization is the final step in reducing size of collagen particles: fiber bundles and particles Older are divided into fibers and fibrils. Preferably, the homogenization satisfies at least one, and preferably all, the following points:

one)

does not affect the fiber / fibril length;

2)

maximize the disintegration of the fiber bundles into fibers / fibrils; I

3)

present a adequate fiber / fibrils ratio.

The previous three points directly influence and strongly in the mechanical properties of the sheet of collagen

While the disintegration steps are fine known in the treatment of collagen, the present method has not previously contemplated by those skilled in the art. The The present invention may employ a conventional homogenizer or a Coloidal Windmill. The homogenization step can be carried out with the same machine as the milling step described above. However, in homogenization, the mass of material that is homogenize has the final composition (water content, content in collagen, softener content, pH, temperature), as long as that the milling step described above is carried out before final adjustment of these parameters. Thus, during the passage of homogenization, the material is milled to less than 1 mm, by example by pressing through plates provided with holes of less than 1 mm, or with the help of a homogenizer or mill colloidal

He passed XIII

(Extrusion, rolling and drying)

Next, the pasta is preferably subjected to extrusion, rolling and drying steps. In this sense, The paste is first carried through a slotted extruder. The extruded paste that passes through the extruder is received on a conveyor belt The paste is preferably laminated (by example, with a rolling mill). The extruded paste is also preferably neutralized (for example, directly after extruder) The neutralization is preferably carried out with gas ammonium, or with sodium hydrogen carbonate, or with other agents of neutralization. It should be noted that, before entering the Extruder, the paste has a pH of approximately between 2.0 and 3.6. TO these pH levels, the collagen particles are swollen (it is say they have a high water content). This high content of water typically leads to collagen deformation at all levels (for example, molecules, microfibrils, elementary fibers, fibers) Direct drying of the paste without neutralization can lead to a fixation of these deformations, so that the interaction of collagen molecules is limited and the weakened sheet resistance. So, for the above, after of the extrusion and before drying, preferably a fiber formation step. This step of fiber formation can understand neutralization to higher pH values, so anterior, or a coagulation with strong solutions highly ionic

The chemicals used for this training of fibers and the exposed time for fiber formation can influence the properties of the collagen sheet. Ammonium gas, cited above, acts very quickly and therefore can assume some disadvantage to the formation of good fibers. He sodium hydrogen carbonate, also mentioned above, acts slowly and, consequently, can improve the formation of fibers and mechanical properties of the collagen sheet. Prior to the present invention, it was not previously contemplated the use of sodium hydrogen carbonate in this context of collagen treatment

\hbox{60 cm}

(este tamaño, empero, puede variar dependiendo de las circunstancias).Preferably, the conveyor belt then passes through a dryer. In the dryer, the neutralized paste is preferably dried on the belt with air at about 60-90 ° C. The length of the dryer can be, simply by way of non-limiting example. approximately 50 meters The conveyor speed (eg, the production speed) should be adapted according to the length of the dryer. In a non-limiting example, when the dryer length is approximately 50 meters, the conveyor speed (directly related to the production of collagen sheet) can be between 3 and 9 meters per minute. Preferably, the transverse width of the sheet on the conveyor is up to about

 \ hbox {60 cm} 

(This size, however, may vary depending on the circumstances).

The present invention for the production of Collagen film made from pig bark differs substantially from the prior art, which employs layers bovine laminar hair free of very low fat content, collected in having them. Therefore, the problem associated with the present invention, that is, the degreasing of very fatty material and the bristle suppression, is unknown in the prior art of Manufacturers of collagen films. The present process of collagen protects the collagen, so it is possible to produce the collagen film without crosslinking agents. The energetic process used for the bovine laminar layers weakens the material, then it is necessary to stabilize the sheet with crosslinking agents. In this technical sector, the exemption of use of crosslinking agents is unknown. Both collagen of altered bovine as the crosslinker lead to a film of collagen with poor stretchability. For the rest, a high stretchability is an important quality criterion. The fats They can improve stretch. For example, patent DE 196 40 019 A1 describes the addition of fat to a dough to obtain a most esteemed collagen film. With the present invention, the swine fat present in the barks of pigs leads to a Collagen sheet with very good stretching properties.

He passed XIV

(Storage)

Next, a step of final storage, for example packaging. Prior to packaging, the collagen sheet is preferably air conditioned (dried). Before packaging, the moisture (water content) of the collagen film should be within the interval between about 5 and 25%, more preferably between about 10 and 20%, and most preferably between approximately 11 and 18% (the humidity level is related, for example, to the passage of softening and with the present conditioning step with air). Among other things, this preferred humidity range provides collagen sheets that are best used. In this sense, humidity levels below about 15% can make collagen films too fragile, while humidity levels above about 20% They can admit an excess of microbiological growth. The product it can have a thickness in the approximate range of between 0.01 and 2 mm, and a dry weight per square meter included between about 10 and 50 g / m2.

The product and its use

As explained before, the product (is that is, the collagen film) produced by the process of The present invention has a number of substantial advantages with with respect to the existing collagen sheets produced with the current procedures These advantages may include, for example, that:

-

From it At the time of sacrifice, the count of microorganisms, and there may be substantially no increase in The microorganism count. The present sheet can be manufactured free of pyrogens and other metabolic products of microorganisms

-

 The new blade It can show a higher content of natural fats. The sheet can therefore be less water absorbent and also more elastic. Therefore, the sheet may require less amount - or even none - of chemical emollients. Besides, the reduced water absorbance can improve the malleability of the sheet.

-

 The product of the The present invention may also have a better native structure. The sheet may be more elastic, more stable, and may not need but a minimum treatment - or even none - with agents of chemical crosslinking

-

 The present product (thanks to the smoother manufacturing process) can have a higher isoelectric point, which reduces water absorption in the natural interval. The sheet, thus, is more stable and is more malleable.

As described above, the present product has substantial benefits in applications in that the collagen sheet is used for with edible products or where the requirements for such collagen sheet are similar to those of edible sheets (for example, when you want a little pollution). In the most preferred embodiment, as shown in Fig. 1, the present sheet F is used in methods of sheathing food products P. More preferably, the present product is used in methods of sheathed with meats and similar food products. In the most preferred embodiment of all, the sheet is used to holster `` hams. '' As indicated below, experts in the art will understand that the present invention has a diversity of benefits and jobs that are applicable to a wide range of Applications.

Normally, the collagen film leaves the very fragile dryer (due to the very low water content). The Freshly made collagen film is difficult to manipulate. This Highly dry film shows great affinity to water. The Water and moisture absorption is fast and difficult to control. For him consumer, the very rapidly absorbing collagen film of water is difficult to control The unused collagen film immediately absorbs a large amount of water from the moist air. He result can be a very sticky sheet, very difficult to manipulate in machines. After a few days, the growth Microbiological in the sheet can also be a problem.

The incorporated natural residual fat makes the This product is stable against variations in humidity. The Collagen sheet comes out of the dryer with a water content residual preferably between 11 and 13%. Even in humid air conditions, this water content is stable and increases at most to a stable maximum of approximately fifteen%.

\hbox{2000 g/m ^{2} }

d bar, mientras que en la presente invención está en un rango de entre 100 y 300. Con la presente invención, los productos no ahumados quedan mejor protegidos contra la oxidación química y la pérdida de agua.Porcine collagen fibers are much thinner than bovine fibers. The resulting pig foil is a much more compact woven material. This positively influences some important properties for use as a sheath, for example, oxygen permeability and moisture permeability. The normal oxygen permeability is approximately between 1000 and 200 ml / m 2 d bar, while the present invention is in a range between 200 and 500. The normal humidity permeability is also between 1000 and

 ? 2000 g / m2 

d bar, while in the present invention it is in a range of between 100 and 300. With the present invention, non-smoked products are better protected against chemical oxidation and water loss.

The present invention can be used for sheath hams in which a collagen film is transformed in a tube and the ham is arranged inside the tube. Therefore, The ham is wrapped in a net. The present invention acts also as a barrier membrane reducing water losses of cooked ham and roast beef. The present invention allows also that the network can be easily removed.

The present invention can be used for production of smoked ham, cooked salted meat products, roast beef, scalded sausages and other types of sausages, Fish and pastry products. The barrier membrane according to the invention protects against water loss, fat loss, etc.

Example 2

He passed one

(Pretreatment)

In a first step the barks are washed with a surfactant

In a specific non-limiting example, this pretreatment can be carried out in the manner described next. It should be understood that this is an example of realization and that can be modified in the appropriate way by experts in the technique, depending on the circumstances (the more values preferable are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 25ºC
(20ºC) \\ (i) placing the following in the mixer: \\ \ quad
Crusts \ + 100% \\ \ quad Water \ + 50 - 200% \ + (100%) \\
Surfactant \ + 0.2 - 3% \ + (1%) \\ (ii) Time of
mixer treatment: \ + 30 min - 4h \ + (1
time) \\ (iii) Rinse: \\ \ quad Remove water and water from the mixer
chemical products
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed II

Alkaline treatment / hair removal (i.e. suppression or removal of pig sows)

In a second step it is removed from the bristles pigs the hair (for example, the roots inside the skin). The presence of this hair is a particular problem in the case of Pigskins In this step of `` hair removal '', to dissolve these undesirable materials from hairs or bristles, it is used a combination of chemicals, which preferably include sadistic sulfide This step, as well as the advantages that derive from same, they are also unknown in the prior art of the field of Edible sheets. Normally, this removal step of The hairs take place in the would you have in technical conditions. Such As already said, the removal of pig hairs with Sulfur in food conditions is new.

In a specific non-limiting example, this hair removal can be done as follows (the most preferable values are in brackets):

         \ begin {tabular} {lcc} Temperature: 10 - 25ºC
(20ºC) \\ pH> 9 (> 12) \\ (i) Place in the mixer: \\ \ quad
Quicklime \ + 0.5 - 5% \ + (3%) \\ \ water \
20 - 50% \ + (30%) \\ \ Sodium sulphide \ +
2 - 6% \ + (4%) \\ (ii) Treatment time in the
mixer: \ + 2 - 8h \ + (5 h) \\ (iii) Add in the
Mixer: \\ \ quad Water \ hfill rest up to \ + 100% \ + (70%) \\ (iv)
Mixer treatment time: \ + 5 - 30 min
\ + (10 min) \\ (v) Rinse: \\ \ quad Remove water from the mixer and
the chemical products
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed III

(Washed)

Next, pig skins are preferably subjected to a washing step. In an example no limiting, the washing step can be carried out in the manner following (the most preferable values are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ (i) Place \ + in the mixer: \\ \ quad Water \ +
50 - 200% \ + (100%) \\ (ii) Treatment time in the
mixer: \ + 5 - 30 min \ + (10 min) \\ (iii)
Rinse: \\\ quad Remove water and products from the mixer
dissolved chemicals. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed IV

(Degreasing)

In this step of degreasing the crusts are defatted Preferably, this degreasing step is carried out. enzymatically with the help of wetting agents (for example, detergents) To hydrolyze the natural fats present between collagen fibers, preferably lipases are used. Further, to assist in this action (that is, to provide a more uniform degreasing) proteases are preferably used. Further, to emulsify the released fatty acids it is preferably used a surfactant This first step, including the combination of chemical products and biochemical agents used therein, and the advantages that derive from them, were not contemplated previously in the field of sheet preparation groceries.

In a specific non-limiting example, this degreasing can be done as follows (should be understood that this is an exemplary embodiment and that it can be modified from the appropriate form by those skilled in the art, depending on the circumstances) (the most preferable values are among parenthesis):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ pH 8 - 13 (9 - 11) \\ (i) placing the following in the
Mixer: \\ \ Quad Water \ + 50 - 200% \ + (100%) \\
Over fat solvents (lipases): \ +
0 - 2% \ + (0.6%) \\ (ii) Treatment time in the
mixer: \ + 15 min - 6h \ + (1 hour) \\ (iii) Add to
The above in the mixer Over protein solvents
(proteases): \ + 0 - 2% \ + (0.5%) \\ \ Surfactant
\ + 0,05 - 3% \ + (0,5%) \\ (iv) Treatment time in
the mixer \ + 1 - 12 h \ + (4 hours) \\ (v) Rinse: \\ \ quad
Remove water and chemicals from the mixer
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed V

(Second wash)

Next, the pig barks are subjected preferably a second wash step. In an example no limiting, the second washing step can be carried out of the following way (the most preferable values are between parenthesis):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30ºC) \\ (i) Place in the mixer: \\\ Water \ +
50 - 200% \ + (100%) \\ (ii) Treatment time in the
mixer: \ + 5 - 40 min \ + (20 min) \\ (iii)
Rinse: \\\ quad Remove water and products from the mixer
dissolved chemicals. \ hskipminus2cm \ hbox {} \\ (iv) Place in the
Mixer: \\ \ quad Water \ + 50 - 200% \ + (100%) \\ (v)
Mixer treatment time: \ + 5 - 40 min
\ + (20 min) \\ (iii) Rinse: \\ \ quad Remove water from the mixer
and the chemicals
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed SAW

(Neutralization)

After degreasing, a neutralization. In this step, the barks of an example do not limiting, neutralization can be carried out in the manner following (the most preferable values are in parentheses):

         \ begin {tabular} {lcc} Temperature: 10 - 35ºC
(30 ° C) \\ pH max. 3.5 \\ (i) Place in the mixer: \\ \ quad Water \ +
50 - 200% \ + (100%) \\ \ quad Citric acid \ +
0.5 - 2% \ + (1%) \\ (iii) Treatment time in the
Mixer: \ + 2 - 5 h \ + (3 h) \\ (iv) Rinse: \\
Remove water and chemicals from the mixer
dissolved. \ hskipminus2cm \ mbox {} \\ (v) Place in the mixer \\
Water \ + 50 - 200% \ + (100%) \ Citrate
monosodium \ + 0.5 - 5% \ + (2%) \\ (vi) Time of
mixer treatment: \ + 2 - 5 h \ + (3 h) \\
Adjust the pH with hydrochloric acid (10%): \\ (vii) Add to
above in the mixer \\ \ hydrochloric acid (10%) \ +
0.2 - 2% \ + (1%) \\ (viii) Treatment time in the
mixer: \ + 30 min - 5 h \ + (2 h) \\ (ix) The
Mixer allowed to stand overnight \\ (x) Rinse: \\ \ quad
Remove water and chemicals from the mixer
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

He passed VII

(Additional wash)

In a non-limiting example, this washing step Additional can be carried out as follows (values more preferable are in parentheses):

         \ begin {tabular} {lcc} Temperature:
10 - 35ºC (30ºC) \\ (i) Place in the mixer: \\
Water \ + 50 - 200% \ + (100%) \\ (ii) Time of
mixer treatment: \ + 5 - 40 min \ + (20
min) \\ (iii) Rinse: \\ \ quad Remove water and water from the mixer
chemical products
dissolved. \ hskipminus2cm \ mbox {} \ end {tabular}
      

The material is milled in the form of a paste of collagen which is then acidified to obtain a mass geliform

He passed VIII

(Grinding)

Same as in Example 1

He passed IX

(Trituration)

The milled material is mixed with 5 parts of water and 3 parts of ice. It is crushed in a colloidal mill until Get a uniform collagen paste.

He passed X

(Preparation of the dough)

In a next step, the paste is preferably mixed again with water, ice, hydrochloric acid and softener to form a uniform geliform mass.

In a case of non-limiting example, the values of the mixed mass can be approximately:

         \ nobreak \ vskip.5 \ baselineskip \ centering \ begin {tabular} {lcc}
Collagen content: \ + 1 - 2.5% \ + (1.8%) \\
Glycerol: \ + 0 - 1.2% \ + (0.6%) \\ pH: \ +
2 - 3.6 \ + (2.8%) \\ Temperature: \ +
3-18 ° C + (8 ° C)
\\\ end {tabular} \ par \ vskip.5 \ baselineskip
      

Although the present invention has been shown and described in relation to preferred embodiments currently being considered as the best modes of implementation of the invention, it is understood that different changes can be made to adapt the invention to the different embodiments, without departing from the broadest inventive concepts disclosed here and that are included in the following claims.

Claims (20)

1. Method of manufacturing a membrane collagen from pig bark material, essentially consisting of the following steps:

to)

chemical degreasing of pig bark material to remove most of the bark material fats;

b)

chemical removal from the hairs of the bark material;

C)

hydrolyzing bark material acidic;

d)

reduction of bark material to a geliform mass of bark material containing collagen; Y

and)

extrusion, lamination and drying of the geliform mass, to obtain a membrane of collagen,

in which steps a) to e) are performed without substantially denature said collagen so that it obtains said membrane of collagen 2. Method according to claim 1, which includes also the step of removing pig skins and freezing them to provide the aforementioned crust material before proceeding to its degreasing 3. Method according to claim 1, wherein said bark material is degreased in such a way that the collagen membrane produced by the method has a fat content of approximately 10% or less, relative to dry weight of the collagen membrane. 4. Method according to claim 1, wherein said operation of removing the hairs from the bark material consists of the alkaline treatment of said bark material to a suitable pH for hair removal. 5. Method according to claim 4, wherein, After the hair removal step, the material of Bark is washed. 6. Method according to claim 5, wherein, After washing, the bark material is treated with a sufficient amount of peroxide to perform the sizing and a sufficient amount of sodium hydroxide to perform separation of collagen fibers. 7. Method according to claim 6, wherein after treatment with peroxide and sodium hydroxide, the bark material is subjected to a second washing step with Water. 8. Method according to claim 6, wherein after the acidic hydrolyzing of the bark material, the bark material is subjected to a water wash step until obtain a pH between approximately 1.8 and 3.9. 9. Method according to claim 1, wherein the bark material is reduced to a geliform mass by milled 10. Method according to claim 1, wherein the geliform mass is mixed with a quantity of a softener enough to soften the membrane, selected from a group consisting of dialcohols, trialcohols, polyols and polymeric sugars. 11. Method according to claim 9, wherein after grinding, the geliform mass is homogenized to provide a substantially uniform water distribution in the dough and divide the collagen from the dough into fibers and fibrils. 12. Method according to claim 1, wherein The geliform mass has a pH between 2.4 and 3.6 before extrusion 13. Method according to claim 1, wherein the collagen membrane has a moisture content comprised between approximately 11 and 18%. 14. Collagen membrane manufactured by the method of claim 1. 15. Collagen membrane according to claim 14, characterized in that it comprises an edible sheet containing primary collagen derived from pig skin. 16. Collagen membrane according to claim 15, wrapped around a food product. 17. Collagen membrane according to claim 16, being the ham food product. 18. Collagen membrane according to claim 15, which has a moisture content in the range Approximately between 5 and 25%. 19. Collagen membrane according to claim 15, which has a thickness in the approximate range between 0.01 and 2 mm. 20. Method according to claim 1, wherein Steps a) to e) are performed without adding softener to obtain said collagen membrane.